On existing levelling devices consisting of adjustable legs/machine feet for use in locations with high requirements for hygiene and with spindles below a certain diameter are today typically used a sleeve, which is mounted from above around the spindle, to shield the thread on the spindle. Sleeve in this connection technically describes a thread shielding.
The sleeve is mounted from above, since there lowermost on the spindle can be an area with a larger circumference than the outer circumference on the spindle's thread, which prevents that the sleeve can be mounted from below.
The thread on the spindle must be covered with a shielding, since cleaning a thread with small edges and sharp corners is very difficult. It is also a requirement that the thread on the spindle is shielded in connection with achieving authority approvals of a levelling device, including USDA, EHEDG and 3A approvals.
This sleeve seals with a lower sealing item lowermost towards the spindle below the spindle's thread and uppermost with an upper sealing item towards the underside of an item, which must be supported by the levelling device, such that filth and bacteria cannot enter into the thread on the spindle. It will be described in a mounting instruction that you may not screw the sleeve so high up that the lowermost part of the thread on the spindle becomes visible.
There are, however, certain drawbacks of the known technology, including that it is possible to screw the noise shielding so far up that the lowermost sealing item is led with the sleeve up over the thread on the spindle and the thread on the spindle is hereby partially exposed and filth and bacteria can enter into the thread and also up below the sleeve, since the lowermost sealing item can not seal against the thread itself on the spindle. This occurs despite it being described in the mounting instruction that the sleeve must not be screwed so high up.
It is furthermore expected that the authority approvals of the levelling device, including at USDA, will make demands concerning that neither the whole thread nor parts of the thread on the spindle can be exposed by a potential faulty use.
DK176705 includes an adjustable leg for levelling and support of items such as machines and as stated in the introduction. By the stated machine foot, there is a risk that the lower part of the thread on the spindle is exposed by mistake.
U.S. Pat. No. 2,592,942 shows a levelling device for levelling and support of items, which levelling device includes at top part suitable for fastening in an item, such as a machine and a lower part for contact against a base. Included in the construction is a spindle with a thread. Upper and lower sleeves are provided around the spindle, the lower sleeve being fastened to the spindle, the upper sleeve being fastened in the item.